Problem: Tiffany ate 4 slices of pizza. Umaima ate 2 slices. If Tiffany ate $\dfrac{4}{10}$ of the pizza, what fraction of the pizza was eaten?
If 4 slices represent $\dfrac{4}{10}$ of the pizza, there must have been a total of 10 slices. $\text{fraction of pizza eaten} = \dfrac{\text{number of slices eaten}}{\text{number of slices total}}$ They ate ${6}$ out of $10$ slices. They ate $\dfrac{6}{10}$ of the pizza.